Process of producing photographs in permanent pigments



- water.

- UNiTn STATES ATENT FFICE.

IVILLIAM W. SHERMAN, OF MILWAUKEE, VISCONSIN.

PROCESS OF PRODUCING PHOTOGRAPHS lN PERMANENT PIGMENTS.

5PECIE'ICATION forming part of Letters Patent No. 332,86 dated December15, 1885.

Application filed July 1, 1884. Serial No. 136,573. (No specimens.)

To all whom it may concern.-

Be it known that I, \VILLIAM W. SHERMAN, of Milwaukee, in the county ofM ilwaukee,and in the State of lVisconsin, have invented certain new anduseful Improvements in a Process of Producing Photographs in PermanentPigments, &c.; and I do hereby declare that the following is a full,clear, and exact description thereof.

My invention relates to a process for making photographic impressionsfor the use of artists, either professional or amateur, whichimpressions are designed to be finished in crayons, pastels,india-ink,watercolors, or oil-colors, as preferred; and itconsists inthe following steps, in the order named: First, coating paper, canvas,or cloth with a sizing of suita ble solubility; secondly, theapplication to the same, in the form of a fine spray,of a pigmentsuspended in a vehicle capable of being made sensitive to the action oflight; thirdly, the exposure to light in the usual manner of producingphotographic prints from a negative; and, fourthly, the development ofthe image by washing away the parts not. acted upon by the light, aswell as partially washing away the parts only partially acted upon bythe light to secure a gradation of light and shade.

I prepare two stock solutions, which I call No. 1 and No. 2,respectively, the first being used in the sizing of the paper and thesecond in connection with the first, together with pigments and asensitizing-salt, in preparing the paper for printing.

I prepare my stock solution No. l by soaking Nelsons photographicgelatine, No. l, in cold water for fifteen minutes, pouring off thewater not taken up by the gelatine, melting the residue by the aid ofheat,and filtering.

To size the paper, take one part of the stock solution No. 1 and dilutewith three parts of The paper may be floated on the sizing-solution ordrawn through it, or the sizing may be applied by means of a brush,theob- 4 5 ject being to evenly coat the surface to receive theimpression. After sizing the paper is allowed to dry.

My stock solution No. 2 is made by soaking Ooignets gelatine half anhour in cold water,

pouring off, as before, the water not taken up by the gelatiue, and thenmelting the residue by the aid of heat, adding to the melted mass sixtimes its bulk of water, and filtering.

To prepare the paper for receiving the impression, I take one-half (ifluid ounce of each stock solution Nos. 1 and 2 and add one and one-half(ll) drams of a saturated solution of bicromate of potash andasufficicnt quantity of pigment, previously mixed with water, to produceresults of the desired depth,

together with enough water to make the entire mixture two fluid ounces.This mixture is thrown onto the paper by means of an atomizersuch as isused by physicians-operated by means of a continuous current of air froma suitable air-pump, or it may be applied by means of the air-brush, allof which operations to be performed in non-actinic light, as well known.The paper is ready for exposure as soon as dry,which exposure iseffected in the usual manner by allowing the light transmit ted througha negative to fall on the paper. The time of exposure varies with thecharacter of the negative and the intensity of the light, but is aboutone-tenth. of that required by the ordinary silver process under thesame conditions. After exposure the paper is immersed in water oftemperature from 80 to 120 Fahrenheit, which in a few minutes generallysuffice to dissolve the gelatiue in the unexposed parts. The paper isthen placed on a frame covered with sheeting and washed wit-h a spray ofwater consisting of a number of small jets having sufficient force todislodge the particles of pigment and gelatine from the parts not actedupon by the light.

\Vhile the solutions that I have described are such as I prefer to useunder ordinary circumstances, these may be varied somewhat, at the willof the operator, under other circumstances. A sizing-solution of lesssolubility tends to produce results having sharper contrasts, the samebeing true with regard to the solutions with which the pigments aremixed, and in preparing the paper for printing I may substitute asaturated solution of bichromate ofammonia for that of potash,to securea great er degree of sensitiveness, when required, and

in case a stronger sizing-solution is used than that hereinbeforedescribed it will be necessary to increase the time of exposurecorrespondingly; but the constituents and proportions already named havebeen found generally satisfactory. I

If desired, the solution of bichromate of potash or ammonia may beomitted from the described mixture of pigment,vvater, and solutions Nos.1 and 2, and after this mixture has been sprayed upon the paper andallowed to dry the paper may be sensitized by floating it, face down,upon a solution of said bichro mate.

Among the chief advantages of my process are the following: My method issimple and inexpensive in developing. I avoid all transfer of the filmfrom one support to another, which is necessary in the ordinary methodof pigment-printing, and which requires great skill and care, and in theresulting print I obtain a most desirable texture, the shadows beingfree from heaviness, and the half-tints being open and resemblingthetexture of crayon or the stipple of brush-Work. The prints are aspermanent as any pigment-prints, and, being made with a much smallerproportion" of gelatine,are less liable to deterioration, and

v the paper not being coated with a film of gel atine there is lessliability of the print flaking or scaling off, as-by using my fine sprayI avoid the said glossy film, which, being smooth and without tooth, isparticularly objectionable,

and the dotted or stipple appearance of my work is highly desirable and,I believe, novel" in photography.

tographic impressions, and producing thereon a dotted or stipple effect,substantially as set forth.

2. In the process of producing photographs, the several steps described,consisting of, first,

coating the'surface of the paper or other suitable material with asizing of suitable solubility; secondly, the application, in the form ofa fine spray, to said surface of the pigments suspended in a vehiclemade sensitive to the action of light; thirdly, the exposure to thelight; and, fourthly, the development of the image by washing away theparts not acted up;

on by the light',leaving a dotted or stipple effect upon the print,substantially asset forth.

In testimony that I claim the foregoing I have hereunto'set my hand, atMilwaukee, in the county of Milwaukee and State of Wisconsin, in thepresence of two witnesses.

WILLIAM W. SHERMAN.

Witnesses: V

STANLEY S. SroUT, H. G. UNDERWOOD.

